Browsing by Subject "Morphological changes"

Now showing 1 - 3 of 3

Open Access
Bi2O3 and BiOCl electrospun nanosheets and morphology-dependent photocatalytic properties
(Royal Society of Chemistry, 2014) Babu, V. J.; Bhavatharini, R. S. R.; Ramakrishna, S.
BiOCl and Bi2O3 nanosheet like structures were produced by electrospinning. The morphological changes were observed by changing precursor (BiOCl3 and Bi(NO3)3·5H 2O) concentrations. These nanosheets were analyzed by XRD, which reveals that the crystal structures of BiOCl and Bi2O3 belonged to tetragonal and beta-phase systems respectively. Both nanostructures were employed for the photodegradation of Alizarin Red S (ARS) dye under UV light (<390 nm) irradiation. BiOCl nanosheet like structures exhibited superior photocatalytic activity (PCA) for the degradation of ARS dye and their half-life was estimated from the kinetic plots of PCA. A plausible reaction mechanism is proposed for the PCA and discussed in detail. © the Partner Organisations 2014.
Open Access
Detection of Calcium-induced morphological changes on RBCs by digital holographic microscopy and blinking optical tweezers
(IEEE, 2016) Rad, V. F.; Tavakkoli, R.; Moradi, Ali-Reza; Anand, A.; Javidi, B.
Ca+2 level in the circulating red blood cells (RBCs) takes part not only in controlling biophysical properties, but also affects the membrane composition, and its morphological and rheological properties. Excessive accumulation of Ca2+ within the cells is associated with a number of important pathological diseases. In this paper, by the use of digital holographic microscopy (DHM), we quantitatively analyzed the volumetric behavior of RBC membrane under influence of excess Calcium ions. DHM in a transmission mode is an effective tool for quantitative visualization of phase objects. By deriving the associated phase changes 3D information on the morphology variation of the cells at arbitrary time scales is obtained. Individual cells are immobilized by the use of optical tweezers and are monitored live with DHM system, while the concentration of Ca2+ ions in the buffer is changed simultaneously. We utilized blinking optical tweezers, by inserting an optical chopper to modulate intensity of the trapping laser beam. Blinking optical tweezers, while keeping the cell trapped during the experiments, ensures of minimizing the photo-damage of trapping laser beam on the cell. Our experimental results are in agreement with previous biological studies and predictions, and experimental observations of living RBCs under Ca2+ influence.
Open Access
Phase transformation during mechano-synthesis of nanocrystalline/amorphous Fe–32Mn–6Si alloys
(Elsevier, 2013) Amini, R.; Shamsipoor, A.; Ghaffari, M.; Alizadeh, M.; Okyay, Ali Kemal
Mechano-synthesis of Fe-32Mn-6Si alloy by mechanical alloying of the elemental powder mixtures was evaluated by running the ball milling process under an inert argon gas atmosphere. In order to characterize the as-milled powders, powder sampling was performed at predetermined intervals from 0.5 to 192 h. X-ray florescence analyzer, X-ray diffraction, scanning electron microscope, and high resolution transmission electron microscope were utilized to investigate the chemical composition, structural evolution, morphological changes, and microstructure of the as-milled powders, respectively. According to the results, the nanocrystalline Fe-Mn-Si alloys were completely synthesized after 48 h of milling. Moreover, the formation of a considerable amount of amorphous phase during the milling process was indicated by quantitative X-ray diffraction analysis as well as high resolution transmission electron microscopy image and its selected area diffraction pattern. It was found that the α-to-γ and subsequently the amorphous-to-crystalline (especially martensite) phase transformation occurred by milling development.